<a href="<?php echo $this->href('/paymentpaypal/express-checkout/index', true)?>"
    rel="nofollow"
    ><img alt="<?php echo $this->translate('PaymentPaypal')->__('Click here to pay via PayPal Express Checkout') ?>" 
        src="https://www.paypal.com/en_US/i/btn/btn_xpressCheckout.gif"
    />
</a>